Oracle left outer join query

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梦谈多话
梦谈多话 2021-01-15 01:26
select a,last_note_user,c,d,iso_src
from X,Y,Z
left outer join W
ON (W.last_note_user=Z.userid AND W.user_ten=Y.iso_src)

when I am executing the ab

2条回答
  •  我在风中等你
    2021-01-15 01:43

    It's probably a good habit to not mix ANSI and non-ANSI join syntax as the other responses indicate. However, it is technically possible, by isolating the non-ANSI joins into a subquery:

    create table X as (select dummy a, dummy c, dummy d from dual);
    
    create table Y as (select dummy iso_src from dual);
    
    create table Z as (select dummy userid from dual);
    
    create table W as (select dummy last_note_user, dummy user_ten from dual);
    
    select a,last_note_user,c,d,iso_src
    from (select a, c, d, iso_src, userid FROM X,Y,Z) xyz
    left outer join W
    ON (W.last_note_user=xyz.userid AND W.user_ten=xyz.iso_src);
    
    A LAST_NOTE_USER C D ISO_SRC 
    - -------------- - - ------- 
    X X              X X X       
    
    1 rows selected
    

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